Security unit for a computer disk



FIG. 1 is a top view of the present invention on a zippered file, with the broken line showing for illustrative purposes only and forming no part of the claimed design;

FIG. 2 is an enlarged top view of the invention;

FIG. 3 is a rear view of the invention;

FIG. 4 is a bottom view of the invention;

FIG. 5 is a front view of the invention;

FIG. 6 is a right-side view of the invention; and,

FIG. 7 is a left-side view of the invention. 

The ornamental design for security unit for a computer disk, as shown and described. 